Remember that salt is hygroscopic, i.e. attracts moisture. The end result with shapeways' "stainless steel"
material would be interesting corrosion effects from both the sintered steel and the bronze filler - probably
reddish-brown, green and blue salt, maybe nouvelle cuisine but not food grade.
Silver might work, but would surely be quite expensive. Also the required minimum wall thickness would
probably lead to heavy, clunky objects. Strong&flexible plastic (nylon) sealed with a food-safe lacquer (some
people here have suggested types used for winery equipment) is probably your best bet, but I doubt you will
get official approval from shapeways for this.